Long-term outcomes of local resection versus surgical resection for high-risk T1 colorectal cancer: a systematic review and meta-analysis

Patients with T1 colorectal cancer (CRC) are at high risk for lymph node metastasis and recurrence after local resection (LR) and need surgical resection (SR) for additional lymph node dissection to improve prognosis. However, the net benefits of SR and LR are still unquantified.We conducted a systematic search for studies in which survival analysis among high-risk T1 CRC patients undergoing LR and SR was performed. Overall survival (OS), recurrence-free survival (RFS), and disease-specific survival (DSS) data were extracted. Hazard ratios (HRs) and fitted survival curves for OS, RFS, and DSS were used to estimate the long-term clinical outcomes of patients in the 2 groups.This meta-analysis included 12 studies. Compared with those in the SR group, patients in the LR group had higher risks of death (HR, 2.06; 95% confidence interval [CI], 1.59-2.65), recurrence (HR, 3.51; 95% CI, 2.51-4.93), and cancer-related mortality (HR, 2.31; 95% CI, 1.17-4.54) in the long term. Fitted survival curves for the LR and SR groups revealed the 5-year, 10-year, and 20-year rates for OS (86.3% and 94.5%, 72.9% and 84.4%, and 61.8% and 71.1%), RFS (89.9% and 96.9%, 83.3% and 93.9%, and 29.6% and 90.8%), and DSS (96.7% and 98.3%, 86.9% and 97.1%, and 86.9% and 96.4%). Log-rank tests showed significant differences among all outcomes except 5-year DSS.For high-risk T1 CRC patients, the net benefit of DSS appears to be significant when the observation period exceeds 10 years. A long-term net benefit may exist but may not be applicable to all patients, especially high-risk patients with comorbidities. Therefore, LR may be a reasonable alternative for individualized treatment for some high-risk T1 CRC patients.